The governor of one Belgian jail has been suspended after keys to the cells went missing.
The chaplain of Leuven prison has mislaid his master set and staff fear inmates could have got their hands on them.
It means the lucky prisoner will be able to open any of the 180 cells and the doors that separate the twenty sections.
Officials are trying to get the bottom of the matter.
A number of staff went on strike for several hours on Wednesday in support of the suspended governor.
They returned to work later that evening and maintenance staff are in for a busy few days.
The locks on all the cells are having to be replaced one by one.